This is one of those "discussion" sort of things - my solution at this point is to not say something directly to the person in question, but I have posted several times about the reality of the issue (not their POV-heavy scare tactics!).
I have a Facebook friend who is very, very, dark Green-with-Orange stripes. I'm also Green, but a very light Green, and with Purple stripes. Oranges and Purples don't get along, frequently, because of their significant clashes in ideology, and dark Greens often think light Greens aren't really Green at all, but really Red. In other words, no matter what personal relationships there may be, it's unlikely we will ever, ever agree.
My Facebook friend (someone I'm not close to, but MANY of my real friends are, and we were cordial once upon a time) posts regular, fact-free rants about Topic X, and why Mr. Z should DO!!!!! SOMETHING!!!!Eleventy!!!! about Topic X. These aren't even her rants - they are repostings from some well known, Orange sites. She states agreement with them, and snarks about Mr. Z, but generally just reposts these things. These are truly fact-free postings - and the facts, which are public records, directly contradict both the letter and spirit of what these things say. Some of them to the point of almost sounding (or actually sounding) a bit like the tinfoil-hat brigade. Truly kooky.
I know what my response is, as I stated above. However, I'd love to know how others would handle this, as at some point I may need to change tactics (just for sanity's sake) and I'd like to be prepared. No, unfriending her, or hiding all her posts, isn't an option - she's friends with too many of my real friends, and posts pictures and things from/about people I truly DO like and want to stay in touch with, from events they go to together (they're all in the same city - I have moved far away). I also worry that perhaps ANY tactic is going to be teaching the pig to waltz - leaving me muddy and annoying the pig, with no success.